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玻璃化（英語：Vitrification；來源於拉丁文的「vitreum」或法語的「vitrifier」），是一種將物質轉化為玻璃[1]（也就是非無定形體）的。陶瓷的不透水性，其咎因為在生產過程中發生玻璃化現象[2]。

玻璃化通常是通過加熱至材料熔化，然後快速冷卻液體以使其達至玻璃轉化溫度（Tg），形成玻璃化的固體。某些化學反應也會導致玻璃化。

在化學中，玻璃化是用來描述在無定形體或無序系統中，基本粒子（如：原子、分子等）之間的鍵合變得強於某個閾值時所發生的特徵[3]。熱波動會破壞化學鍵；因此，溫度越低，化學鍵強度越強。因此，無定形材料具有稱為玻璃化轉變溫度（Tg）的特徵閾值溫度：低於Tg的無定形材料是玻璃狀的，而高於Tg的它們是熔融的。

In terms of chemistry, vitrification is characteristic for amorphous materials or disordered systems and occurs when bonding between elementary particles (atoms, molecules, forming blocks) becomes higher than a certain threshold value.[4] Thermal fluctuations break the bonds; therefore, the lower the temperature, the higher the degree of connectivity. Because of that, amorphous materials have a characteristic threshold temperature termed glass transition temperature (Tg): below Tg amorphous materials are glassy whereas above Tg they are molten.

The most common applications are in the making of pottery, glass, and some types of food, but there are many others, such as the vitrification of an antifreeze-like liquid in cryopreservation.

In a different sense of the word, the embedding of material inside a glassy matrix is also called vitrification. An important application is the vitrification of radioactive waste to obtain a substance that is hopefully safer and more stable for disposal.

製陶

玻璃化是由於燒製過程導致的粘土或身體的逐漸部分融合。 隨著玻璃化的進行，玻璃態鍵的比例增加，並且燒製產品的表觀孔隙率逐漸降低。Vitrification is the progressive partial fusion of a clay, or of a body, as a result of a firing process. As vitrification proceeds, the proportion of glassy bond increases and the apparent porosity of the fired product becomes progressively lower.[5][6] Vitreous bodies have open porosity, and may be either opaque or translucent. In this context 'zero porosity'; may be defined as less than 1% water absorption. However, various standard procedures define the conditions of water absorption.[7][8][9] An example is by ASTM, who state "The term vitreous generally signifies less than 0.5% absorption. except for floor and wall tile and low-voltage electrical insulators which are considered vitreous up to 3% water absorption."[10]

Pottery can be made impermeable to water by glazing or by vitrification. Porcelain, bone china and sanitaryware are examples of vitrified pottery, and are impermeable even without glaze. Stoneware may be vitrified or semi-vitrified; the latter type would not be impermeable without glaze.[11][5][12]

玻璃化是由於燒製過程導致的粘土或身體的逐漸部分融合。隨著玻璃化的進行，玻璃態粘合劑的比例增加，並且燒製產品的表觀孔隙率逐漸降低[2]。

Vitrification is the progressive partial fusion of a clay, or of a body, as a result of a firing process. As vitrification proceeds, the proportion of glassy bond increases and the apparent porosity of the fired product becomes progressively lower.[5][13] Vitreous bodies have open porosity, and may be either opaque or translucent. In this context 'zero porosity'; may be defined as less than 1% water absorption. However, various standard procedures define the conditions of water absorption.[14][15][16] An example is by ASTM, who state "The term vitreous generally signifies less than 0.5% absorption. except for floor and wall tile and low-voltage electrical insulators which are considered vitreous up to 3% water absorption."[17]

Pottery can be made impermeable to water by glazing or by vitrification. Porcelain, bone china and sanitaryware are examples of vitrified pottery, and are impermeable even without glaze. Stoneware may be vitrified or semi-vitrified; the latter type would not be impermeable without glaze.[18][5][19]

應用

當蔗糖慢慢冷卻時會產生食糖（或冰糖）；但當迅速冷卻時會形成糖漿狀的棉花糖（或顆粒狀的棉花糖）。

當用液體（如：水）開始時，通常通過非常快速的冷卻或引入抑製冰晶形成的試劑，也會發生玻璃化。這與導致冰晶形成的普通冷凍形成對比。用於低溫生物學或由生活在極地地區的生物自然產生的添加劑被稱為冷凍保護劑。在冷凍電子顯微鏡中使用玻璃化冷卻以快速冷卻樣品，使得它們可以用電子顯微鏡成像而沒有損壞。

冷適於青蛙和其他一些ectotherms自然產生的甘油(例如，南部的棕樹蛙)或葡萄糖(例如，木蛙)在他們的肝以減少冰的形成。當血糖是用作一個冷凍保護北極的青蛙，大量的葡萄糖放在較低的溫度和一種特殊形式的胰島素使用於這些額外的葡萄糖的輸入單元。當青蛙rewarms在彈簧、額外的葡萄糖必須迅速消除，但是保存。極地昆蟲也使用糖作為冷凍保護劑。北極地區的魚使用的防凍液蛋白質，有時附加了糖，作為冷凍保護劑。

普通汽水-石灰玻璃，用於windows和飲水的容器，是建立由外的碳酸鈉和石灰石(氧化鈣)，以二氧化矽的。沒有這些添加劑的二氧化矽會需要很高的溫度以得到一個融和隨後(與緩冷)的一個玻璃。

用於低溫生物學或由生活在極地地區的生物自然產生的添加劑被稱為冷凍保護劑。目前，玻璃化技術只有適用於大腦人體冷凍技術通過Alcor和上身受的人體冷凍研究所，但研究正在進行，由這兩個組織的申請玻璃化的整個身體。

用於處理以及長期儲存核廢料或其他危險廢棄物的玻璃化方法[20]被稱之為「地緣融化（英語：Geomelting）（geomelting）」。Waste is mixed with glass-forming chemicals in a furnace to form molten glass that then solidifies in canisters, thereby immobilizing the waste. The final waste form resembles obsidian and is a non-leaching, durable material that effectively traps the waste inside. It is widely assumed that such waste can be stored for relatively long periods in this form without concern for air or groundwater contamination. Bulk vitrification uses electrodes to melt soil and wastes where they lie buried. The hardened waste may then be disinterred with less danger of widespread contamination. According to the Pacific Northwest National Labs, "Vitrification locks dangerous materials into a stable glass form that will last for thousands of years."[21]

When sucrose is cooled slowly it results in crystal sugar (or rock candy), but when cooled rapidly it can form syrupy cotton candy (candyfloss).

Vitrification can also occur in a liquid such as water, usually through very rapid cooling or the introduction of agents that suppress the formation of ice crystals. This is in contrast to ordinary freezing which results in ice crystal formation. Vitrification is used in cryo-electron microscopy to cool samples so quickly that they can be imaged with an electron microscope without damage.[22][23] In 2017, the Nobel prize for chemistry was awarded for the development of this technology, which can be used to image objects such as proteins or virus particles.[24]

Ordinary soda-lime glass, used in windows and drinking containers, is created by the addition of sodium carbonate and lime (calcium oxide) to silicon dioxide. Without these additives, silicon dioxide will require very high temperature to obtain a melt, and subsequently (with slow cooling) a glass.

Vitrification is used in disposal and long-term storage of nuclear waste or other hazardous wastes[25] in a method called geomelting. Waste is mixed with glass-forming chemicals in a furnace to form molten glass that then solidifies in canisters, thereby immobilizing the waste. The final waste form resembles obsidian and is a non-leaching, durable material that effectively traps the waste inside. It is widely assumed that such waste can be stored for relatively long periods in this form without concern for air or groundwater contamination. Bulk vitrification uses electrodes to melt soil and wastes where they lie buried. The hardened waste may then be disinterred with less danger of widespread contamination. According to the Pacific Northwest National Labs, "Vitrification locks dangerous materials into a stable glass form that will last for thousands of years."[21]

深低溫保存技術

在深低溫保存技術中，玻璃化現象會被運用於貯藏諸如人卵細胞（如卵母細胞；其運用被稱之為「卵母細胞冷凍貯藏」）和胚胎（即「胚胎冷凍貯藏」）等。

Currently, vitrification techniques have only been applied to brains (neurovitrification) by Alcor and to the upper body by the Cryonics Institute, but research is in progress by both organizations to apply vitrification to the whole body.

用於低溫生物學的添加劑或由生活在極地地區的生物自然產生的有機物則被稱為冷凍保護劑。

其他條目

參考資料

  1. ^ Varshneya, Arun K. Fundamentals of inorganic glasses. Sheffield [England]: Society of Glass Technology. 2006. ISBN 0900682515 （English）. 
  2. ^ 2.0 2.1 Arthur, David; Dodd, Murfin. Dictionary of Ceramics. London. 
  3. ^ M.I. Ojovan, W.E. Lee. Connectivity and glass transition in disordered oxide systems J. Non-Cryst. Solids, 356, 2534-2540 (2010).
  4. ^ M.I. Ojovan, W.E. Lee. Connectivity and glass transition in disordered oxide systems J. Non-Cryst. Solids, 356, 2534-2540 (2010).
  5. ^ 5.0 5.1 5.2 5.3 Dodd, Arthur; Murfin, David. Dictionary of Ceramics 3rd. London: The Institute of Minerals. 1994. ISBN 0901716561. 
  6. ^ 'Role Of Accessory Minerals On The Vitrification Of Whiteware Compositions.' N.M.Ghoneim; E.H.Sallam; D.M. Ebrahim. Ceram.Int. 16. No.1. 1990.
  7. ^ Whitewares: Production, Testing and Quality Control. William Ryan & Charles Radford. Institute of Materials, 1997
  8. ^ 'Methods Of Extending The Narrow Vitrification Range Of Clays.' E.V. Glass & Ceramics 36, (8), 450, 1979.
  9. ^ 'Control Of Optimum Vitrification In Vitreous And Porcelain Bodies.' E.Signorini. Ceram.Inf. 26. No.301. 1991
  10. ^ ASTM C242-01. 'Standard Terminology Of Ceramic Whitewares and Related Products'.
  11. ^ 'Body Builders.' J.Ahmed. Asian Ceramics. June 2014 [需要完整來源]
  12. ^ 'An Introduction To The Technology Of Pottery.' Paul Rado, Institute of Ceramics. 1988.
  13. ^ 'Role Of Accessory Minerals On The Vitrification Of Whiteware Compositions.' N.M.Ghoneim; E.H.Sallam; D.M. Ebrahim. Ceram.Int. 16. No.1. 1990.
  14. ^ Whitewares: Production, Testing and Quality Control. William Ryan & Charles Radford. Institute of Materials, 1997
  15. ^ 'Methods Of Extending The Narrow Vitrification Range Of Clays.' E.V. Glass & Ceramics 36, (8), 450, 1979.
  16. ^ 'Control Of Optimum Vitrification In Vitreous And Porcelain Bodies.' E.Signorini. Ceram.Inf. 26. No.301. 1991
  17. ^ ASTM C242-01. 'Standard Terminology Of Ceramic Whitewares and Related Products'.
  18. ^ 'Body Builders.' J.Ahmed. Asian Ceramics. June 2014 [需要完整來源]
  19. ^ 'An Introduction To The Technology Of Pottery.' Paul Rado, Institute of Ceramics. 1988.
  20. ^ Ojovan, Michael I.; Lee, William E. Glassy wasteforms for nuclear waste immobilization. Metallurgical and Materials Transactions A. 2011, 42 (4): 837–851. Bibcode:2011MMTA...42..837O. doi:10.1007/s11661-010-0525-7. 
  21. ^ 21.0 21.1 Waste Form Release Calculations for the 2005 Integrated Disposal Facility Performance Assessment (PDF). PNNL-15198. Pacific Northwest National Laboratory. July 2005 [2006-11-08]. 
  22. ^ Dubochet, J.; McDowall, A.W. Vitrification of pure water for electron microscopy. Journal of Microscopy. December 1981, 124 (3): 3–4. doi:10.1111/j.1365-2818.1981.tb02483.x. 
  23. ^ Dubochet, J. Cryo-EM-the first thirty years. Journal of Microscopy. March 2012, 245 (3): 221–224. doi:10.1111/j.1365-2818.2011.03569.x. 
  24. ^ Nobel Prize in Chemistry Awarded for Cryo-Electron Microscopy. The New York Times. October 4, 2017 [4 October 2017]. 
  25. ^ Ojovan, Michael I.; Lee, William E. Glassy wasteforms for nuclear waste immobilization. Metallurgical and Materials Transactions A. 2011, 42 (4): 837–851. Bibcode:2011MMTA...42..837O. doi:10.1007/s11661-010-0525-7. 

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